Piston for internal-combustion engines



L. V. THOMAS.

PISTON FOR INTERNAL COMBUSTION ENGINES.

APPEICATION FILED JULYB, I919.

Patented Mar. 28,

MOTE'UR EL. THQHIAS, 01 LYGIX, ERA-MGR LOU IS VICTOR THOMAQ; F LYON, FRANCE, ASSIGNOR T0 LA. SOGIETE ANONYLZE D m PISTON FOR INTERNAL-CQHEBUSTION ENGINES.

Applicatlonflled July 6, 1919. serial No. 309,325.

To all 'uihom it may, concern:

Be itknown that I, LOUIS VICTOR Tnonas,

a citizen of the French Republic, of Lyon,

France, have invented certain new anduse- ,ful Improvements in Pistons for-Internal- Combustio'n Engines, of which the following is a specification.

In explosion motors in which the piston I controls the distribution, including twostroke cycle motors with or without valve,

the pistons have, hitherto been comparatively large and complicated, which makes the manufacture thereof diilicult and involves considerable weight, especially in the case of two-stroke cycle pistons and pistons shaped at the base to form a deflector, and the conditions are unfavorable for obtaining perfect balance and high speeds.

In order to partly obviate these drawbacks, such pistons have been made of aluminium, (but. this in no way facilitates the manufacture of the piston. any more than it enables thev piston to be exactly balanced.

- On the other hand, the aluminium, being 25' comparatively-soft, especially at high temperatures, is liable to become worn at the ciently gas-tight I I I The object of this invention is to olwiate these disadvantages. 'According' to the invention the piston is constructed in three parts. 7

a ()ne of these parts, of aluminiumor equivalent light metal or alloy, forming the body of the piston is of perfectly cylindrical shape, open at both ends, all its arts.

Anot ier part, also of aluminium or equivalent light metal or-alloy, formsthe bot tom, and is screwed to the first part: this second part can also beworked throughout. The third part is'of steel and is forced onto'the two other parts: it hasthe grooves or channels for the piston rings.

The various parts are designed in detail as required to fulfil thedistributive funcrings, and for that reason is-not always sulfi- 'tions of the piston in the particulartype of motor in which it is used.

T he invention will now be described with reference to the accompanying drawing,

. showing one form of construction, by way giving access to arranged to register at the proper times with the supply port 0 and the exhaust port ti respectively. It also has a deflector e directing the admitted gases to the top of the cylinder to prevent their mingling with the burnt gases.

The cylindrical part f of the piston, of aluminium, is open at both ends: it is screwthreaded internally at g, in order to receive the head it, also of'aluminium. The latter, with the deflector e which forms part of it, can be easily worked throughoutbefore mounting the part. head with the body can be completed by a band of autogenous solder. 'After joining reduced in diameter over a suitable'part of their length to receive a. steel sleeve jpreviously bored. the piston is finished and the grooves for the rings are cut in the sleeve The sleeve y has the orifices a and b. and the shape of the valve renders it very easy to properly adjust these orifices and to regulate exactly, with respect tothe ports 0 and (I of the cylinder, the times of opening and closing the inlet and the exhaust. The invention allows of first opening the port of the cylinder, discharging products of combustion before theadmission of the fresh gases, and closing the exhaust port during a large part of the period of supply. The two parts are only-open together for a very short time.

What I claim as my invention and desire to secure by Letters Patent of the United States is 1 In an internal combustion engine piston the combination of a cylindrical piston body of light metal externally reduced in diameter at its upper part, a piston head of light metal screwed into the upper part of said cylindrical body, a gas deflector on said piston head, integral therewith, and a steel sleeve fitted upon the reduced upper part of said body, said sleeve extending upwardly around said piston head and said deflector and having ports.

In witness whereof I have signed this specification in the presence of two witnesses.

LOUIS VICTOR THOMAS.

The junction of the Then the outer surface of Specification of Letters r atent. Pmm t fl .ltg 2% 1922 these two members they are turned down or 

